Ms Henderson argued she wanted to seek the expert advice of Attorney-General George Brandis on whether the judges giving evidence in person would breach the principle of separation of powers, which protects the independence of the judiciary from the influence of parliament.

Deputy Chair of the Committee, Labor MP Sharon Claydon, said the efficacy of the inquiry would be hampered without the judges’ evidence, and argued the judges were “highly competent” and able to decide what was appropriate to tell the committee.

But Ms Henderson told the ABC’s AM: “I was concerned, and I think it was very prudent and appropriate…that subjecting judges to questioning and interrogation by members of parliament crossed the very important principle of separation of powers.

“We referred this to the Attorney-General, the Attorney-General agreed that this is a fundamental tenet of our democracy.

“I didn’t think it was appropriate to put judges in a place where they could be subverted to the harassment or the interrogation of members of parliament.”

The judges will still make submissions to the committee in writing.

Ms Claydon led the criticism of Ms Henderson, arguing that the judges had given evidence before parliamentary committees before.

“While judges have appeared before parliamentary committees before, what the Attorney has done is drawn a distinction between judges appearing privately and in relation to the operation and decisions of the courts over which they preside.

“I have no doubt that our inquiry will be quite critical in parts about some of the decisions and processes in the Family Court.”

Major reform needed in family law system

The inquiry is hearing evidence in Alice Springs, where Ms Henderson said some of the failings of the family law system were most keenly felt.

They include serious delays in the court processes and the significant expense of hiring lawyers.

“Too often, family violence is not being ascertained early enough in proceedings and that’s having major impact on orders made by the court, particularly in relation to children and the safety of children,” Ms Henderson said.

“The Northern Territory Government says Aboriginal women are 40 times more likely to be hospitalised as a result of violent assault, most committed by partners or ex-partners as a result of alcohol.

“The rates of non-disclosure are also very high.”

Ms Henderson argued some of the people brought in to compile reports on the parlous state of some families were gouging the system.

“Some of them are charging up to $9,000 a day, it’s absolutely outrageous,” she said.

“Courts rely on family report writers to determine many of the factual matters between warring parents, and particularly involving children.